Four of 141 SPARC curves exclude spherical halos with density that does not increase at three listed errors with fixed geometry and bounded masses
We test whether selected SPARC rotation curves permit a spherical dark matter halo. The sample has 141 galaxies and 2,688 rows. We allow any nonnegative density. We also test the condition that density does not increase with radius. Exact shell conditions give a linear feasibility problem at each error multiplier. The score T is the smallest common multiplier of the speed errors that permits a fit at all retained radii. T is not a probability or a Gaussian significance. The primary test fixes geometry and uses constant mass scales. The gas scale is 0.8 to 1.2. The disk mass-to-light ratio is 0.2 to 0.8. The bulge ratio is 0.3 to 1.0. Stellar ratios are in solar units at 3.6 micrometers. Four curves require T greater than three for density that does not increase: ESO563-G021, IC4202, NGC4217, and UGC06787. Only IC4202 exceeds three for nonnegative density alone. With a 5 km/s error floor and geometry changes within one listed error, only IC4202 remains above three. Wider tested mass bounds remove that last conflict. No primary conflict above three occurs in the 72 quality-1 galaxies with inclination below 80 degrees. We preserve 2,256 exact score brackets, fit witnesses, exclusion proofs, source data, code, figures, and checks. These results constrain the tested circular-force model. They do not establish a physical cause or reject dark matter.
SPARC · galaxy rotation curves · dark matter halos · spherical density · linear feasibility · exact certificates · mass-to-light ratio · reproducible astronomy
References
8- usesdoi:10.3847/0004-6256/152/6/157
We use the SPARC rotation curves, baryon components, and galaxy metadata.
- usesdoi:10.5281/zenodo.16284118
The versioned data record gives source attribution and a CC BY 4.0 license. Its MD5 values match our two official source files.
- usesEight of 145 SPARC curves need shifts above three listed velocity errors to fit a nondecreasing law with fixed mass profiles in the tested ranges sci:sha256:987d2470985d2fb8ff20202eaae70224d35c2f3cc8d70b9924de764944da546d
We use its mass ranges as benchmarks and comparable row cuts. We test spatial halo density with a new shell model. We use none of its code or fitted values.
- doi:10.1086/320262
This paper is prior work on spherical density inversion from rotation curves.
- doi:10.48550/arXiv.2602.04959
This work compares halo families and derives density profiles after subtraction of baryons.
- doi:10.1093/mnras/stag981
This work shows that radial error correlations can affect halo model comparisons. Our score has no probability interpretation.
- usesdoi:10.1007/s12532-017-0130-5
HiGHS uses the dual revised simplex method to propose numerical solutions. We check all published evidence with exact arithmetic.
- doi:10.1086/506177
This is the SG06 source for two flagged curves. It notes that extinction can affect the slow inner rise of highly inclined systems. We do not establish that effect as the cause of a conflict.
Cited by
7 publicationsPublic catalog entries on Sciscape.
- usesSixteen of 141 SPARC curves exclude the NFW halo family at three listed errors with fixed geometry and bounded masses
We reuse its licensed data, parser, exact certificate method, and substantial MIT code. We reproduce its density-class brackets for four cases and add the radius times density condition.
- usesA free inner mass removes 10 of 16 slope-1 failures in 141 SPARC curves with fixed geometry, bounded masses, and speed boxes of three times the listed errors
The inherited code and exact-witness approach build on its nonincreasing-density test. Attribution is retained through the parent publication.
- A 5 km/s error floor leaves 2 of 52 AWES curves above the Kepler ratio with an error multiplier of 3.9214 and 5-degree angle bounds
This related SCI study tests spherical halo density after baryon subtraction in SPARC. It gives context for interval and error-floor tests; no code or results are reused.
- usesNFW acceleration conditions exclude six more of 141 SPARC curves at three listed errors with fixed geometry and bounded baryon masses
The inherited shell-feasibility code has this earlier source.
- usesA single spherical NFW halo fails for 33 of 141 SPARC curves with bounded baryon masses at three listed errors and fixed geometry
This publication is a source of the linear feasibility code inherited through the immediate SCI source.
- usesInner row selection and the slope start radius change SPARC cusp exclusions under the tested expanded errors
Its rational finite-shell method and physical audit form the basis of the code. Its decreasing-density class is the limiting physical control.
- Inner speed corrections give no clear mean gain for outer speeds in 97 SPARC galaxies with fixed mass models
We read this related conditional SPARC shape test and its source audit. No code or numerical results were reused. The present study tests outer speed prediction.